Elevator door



Sept. 18, 1928.

Original Filed May 21, 1925 W. SHONNARD ELEVATOR DOOR 2 Sheets-Sheet 1H. W. SHONNARD Sept. 18, 1928.

ELEVATOR boon 2 Sheets-Sheet 2 Original Filed May 21, 1925 constructedof metal strips pivotally connect- Patented Sept. '18, 1928.

v uurrao STATES- v 1,684,719 Parent OFFICE."

HARGLD W. snonnann, 0F UPPER iYIONTCLAIR, NEW JERSEY, ASSIGNOR T0 ELEVA-TOR SUPPLIES ooiviranx', a CORPORATION or new JnnsnY.

ELEVATOR DOOR.

Continuation of application Serial No. 31,783, filed May 21, 1925.

1926. Serial N0.-156,557.

In my application for United States Letters Patent filed March 17, 1925,Serial Number 16,214- I have described means for avoiding accidentalcatching of fingers and clothing of passengers in doors for elevators,etc,

ed and acting on the lazy tongs principle.

The means in question comprise one or more flexible curtains on a springroller or rollers so arranged that, as the door 1s unfolded in closing,thecurtain unrolls and'presents a shield along the expanding Width ofthe door;

at the same time, of course. winding up the spring on the roller andincreasing its tension. r

In order to prevent sagging of the flexible curtain so used it isnecessary to employ roller spring of very considerable tension; and, inconsequence, it has been found that the pull of the curtain on a closedelevator door is sufficient to open the door to some extent, unless itbeheld or locked closed, which is not acceptacle in practice. Thisaccidental opening of the elevator door is particularly undesirable inthe-numerous cases in which an electric interlocking switch is sooperated by the closure of the door, even a little distance, in suchcases, acts to bring the elevator cage to a stop at once. I

The present invention has relation to'means for preventing alldisadvantages arising from the tension of the roller spring of; myimproved flexible shield above mentioned, these means involving acounter-balancing device adapted to easy application to an elevatordoor, and fitted for accommodation within the restricted space availablein standard elevator structures.

In some cases it is the practice to provide automatic closing devicesfor elevator doors, and, where unbalanced spring-roller shields areused, these power closers have to be specially adjusted for use witheach door, owing to diiferences in spring tension and in the range ofdoor movement. My present invention renders such adjustment generallyunnecessary, as the disturbing influence of each spring-pulled shield orcurtain is removed. The present application is a continuation of mypatent application for closing means for elevator doors, filed May 21,1925, Serial No. 31,783 which has become abandoned.

unextended length.

This application filed December 23,

My invention is illustrated in a preferred form in theaccompanyingdrawing wherein Figurelis a view in elevation of a mechani-;

cal ly operated door equipped with my inven tion, Figure 2 is a view onalarger scale of -my spring counterbalance, as seenin elevation, Figure3 is a plan view of the same, and Figure 42 is a perspective view of apreferred form of attachment for the tension chain.

In the particularform shown in'the drawings, the door is operated by aform or" me chanical neans' set forth and claimed in another patentapplication. This comprises a compressed air engine 7 acting through aswinging arm 8 which has as'liding attachment 9' with the door or gate.This forms no part of the present invention, as any appropriate form ofmechanical door operator may be used in connection with the inventiondescribed below. i

The well known lazy tongs door or gate is composed of parallel verticalbars 10 united by diagonal bars 11, pivotally connected with each otherand slidingly connected with the verticals. As the door is expanded toclose it, the verticals move apart retaining their parallelism and thediagonals make an increasing angle with each other. 9 l The flexibleshield of my aforesaid pending application comprises a curtain 12, whoseouter edge is fixed to the outer edge of the door or gate, as shown.This curtain car riedbya spring roller 13 fixed usually to the doorjamb, as shown. It will be clear that the constant tension of the springroller 13 acts through the curtain 12 to tend to open the door.

Inorder to counterbalance this tendency, I employ one or more helicalsprings 1 1, so arranged as to pull the door shut. of this kind cannotbe extended in practice for more than about thirty percent of their Anextension materially greater than this carries them beyond the elasticlimit, and soon renders them useless. It'is clear, therefore, that if aspring or spring-group were attached to the outer edge of the unfoldingdoor or gate, the extension of the springwould have to be at least asgreat as the entire width of the door opening. Consequently it would benecessary to use a spring group about six feet long. This would beawkward in any connection,

Springs but it is quite imir'aracticable inv elevator practice, because"the entire equipment: for each elevator has to be placed within thelateral limits of its own shaft and cage.

My invc1rt'ron, in its preferred form, therefore, comprises aconstruction such asto permit a practical spring to be located Withinthe{width of the elevator cage, which is very generally only slightlygreater than the door. opening itself.

I For this purpose I preferably employ a tension. member havinga' springor spring group 14, one end of which tension member bracket has adeep-slot17,o

of a hammer on. the bracket 16.

is fixed, as shown, to an extensionv 10 cache of the verticalbars 10-contiguous to the j-a-mbwhereon the door is hung. In the. drawing" thesecondmovable vertical is shown, but the: choice of verticals for thispurpose will depend uponthe maximum distance between verticals, tl'1estrength o-fthe spring group etc.

The opposite end of the tension member preferably consists of a chain15- which is fixed to a. suitable fastening on that side of the doorframe opposite to the j amb' uponi which it is hung. In order to suit agiven catching one or another of the links of the chain 15 in theslot17. v 7

If desired, the opening of the slot 17 can be more or' less closed afterinsertionof thechain, so asto hold it in place,by a few taps T his lastvnamed feature makesit possible to use. thesame tension member on rightor lefthanded doors at'will.

WVheni attached as shown: in the drawing the chain 15 lies in a slot.1'1 open at the top, and the slot need not be closed,;as the chaincannot fall out. The; same tension member could, however, be used with adoor opening oppositely to that shown, in! which case; the slot 17 wouldbe inverted and would have tobe closed asabovedaecnibed toproiventtheclmdn from falling out.

ratio of the total horizontal movement of a given vertical bar 10 to thewidth of the door" openingis expressed" by a; fraction whose denom natoris the number of spaces between verticals and whose numerator is thenumber of such spaces between. the. given vertical. and v the, door amb;it is clear that the total travel" of one of the verticals contiguous tothe jamb is in that ratio. smaillerthan the width of the door opening:Consequently, whenthe ten-- It will now be seen that, inasmuch as thesion member is mounted as shown, its: totalextension during use ismuchless than if it were attached to the front edge of the door; Thismakesit possible therefore, toaccommodate the entire door closingcounterbalance within the width of the elevator cage.

What I claim. is V v 1. In combination with an elevator cana gate,mechanical means for operating the;

same, as ring operated fender on thegateamd. a sprlng avin one endattachedto the frame. of the gate. an -the other end attached to.- thebalance the tension of the fender spring so as to prevent disturbance ofthe a'ctlon of the gate operating means.

2.. According springcomprismg anextensible helical 5 ring or springs, achain attached to one end ere.- of, and a slotted bracket adapted. tovengage.

to claim 1, the counterbalance,

gate, said spring being adaptedto counter- V with one oranother link ofsaid. chain. to: permit adjustment of the spring, tension. at wilL. 3.According to claim: 1. the. counterbalance spring comprising anextensible helical sprin or springs, a chain attached. toone end thereoandareversible bracket having a slot adapted to be partly closed andadapted to engage with one or another link of said chain topermitadjustment of the sprin tension atwilL 4. In an elevator care; 9 azytongs gate for the same: having. vertical bars and cross bars pivotedtosaid verticalbars. a spring, operated fender onusaid: gate, andaspiring having one end attached to the frame. of the; gate and. the.other end attached toan: exten sion on a vertical bar thereof near themom able outer edgesof the gate,

In testimony whereof I an. m. sigma;

V HAROLD wesno NARI).

